I had unprotected sex close to 2 weeks ago and the day after there was a burning sensation when I first peed but that went away.  However, I developed a few small bumps around my inner labia, right outside of the vagina opening.  It's very itchy, but not at all painful. I washed it with some diluted raw acv and that seemed to provide some relief.  What do you think it might be? And does anybody know any more methods to reduce itchiness?

background that might be relevant:

- I had an iud inserted over a month ago, had some funky discharge, but gyno said it was because of the string changing the ph/bacterial level and should stabilize